水泥混凝土桥面水泥基防水黏结层材料性能评价

    Performances of Cement-based Waterproof Adhesive Layer in Cement Concrete Bridge Deck

    • 摘要: 为了使水泥混凝土桥面水泥基防水黏结层兼具优异的防水性能和黏结性能,开发了一种新型水泥基防水黏结层材料,选用3种传统沥青基材料(SBS改性沥青、橡胶沥青、水性环氧树脂改性乳化沥青)与其进行性能对比.通过剪切试验确定了水泥混凝土桥面板的最佳处理方式以及水泥基防水黏结层材料的最佳凝结时间.利用斜剪和拉拔试验分别评价了不同温度、浸水和冻融循环等因素对水泥基和沥青基防水黏结层材料强度的影响规律.试验结果表明:水泥混凝土桥面板宜采用拉毛处理,水泥基防水黏结层材料的最佳凝结时间为0.5 h;随着温度的升高,水泥基和沥青基防水黏结层材料的剪切和拉拔强度均呈线性下降,但水泥基防水黏结层材料的剪切和拉拔强度下降幅度明显低于3种沥青基材料,在70℃高温条件下,3种沥青基材料的剪切和拉拔强度接近0 MPa,而水泥基材料的剪切和拉拔强度仍能分别达1.37、0.36 MPa,说明水泥基防水黏结层材料的耐高温性能优异;浸水和冻融循环对水泥基防水黏结层材料的剪切和拉拔强度的影响远小于其对沥青基材料的影响,这主要得益于水泥基防水黏结材料在有水条件下持续的水化反应.

       

      Abstract: To develop and evaluate performances of a new cement-based waterproof adhesive layer in cement concrete bridge deck, three traditional types of asphalt-based materials (SBS modified asphalt, rubber modified asphalt, and water-based epoxy resin modified emulsified asphalt) were compared. The best treat method of cement concrete bridge deck and the optimal setting time of cement-based material were determined by shear tests. The influences of different temperatures, water immersions and freeze-thaw cycles on strength of cement-based and asphalt-based materials were evaluated by using shear and pullout test respectively. The test results show that cement concrete bridge deck should be roughed and the best setting time of cement-based material is 0.5 h. With increasing temperature, the shear and pullout strength of cement-based and asphalt-based materials linearly declines; however the shear and pullout strengths of cement-based material are significantly lower than that of asphalt-based materials. The shear and pullout strengths of the three asphalt-based materials are close to 0 MPa at 70℃; however the shear and pullout strength of cement-based material can reach 1.37 MPa and 0.36 MPa, which indicates that the cement-based material has excellent high-temperature performance. The effect of water immersion and freeze-thaw cycle on the shear and pullout strength of cement-based material is much less than that of asphalt-based material, due to its continuous hydration reaction under water condition.

       

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